Astronomers Have Discovered One of The Most Massive Objects in the Universe

Advertisement

Through
the thick fog of our own galaxy, astronomers have spotted an ultimate prize:
one of the largest-known structures in the Universe. Called the Vela
supercluster, the newly discovered object is a massive group of several galaxy
clusters, each one containing hundreds or thousands of galaxies.

"I
could not believe such a major structure would pop up so prominently"
after an observation of that region of space, said Renée Kraan-Korteweg, an
astrophysicist at the University of Cape Town in South Africa, in a press release.

Kraan-Korteweg
and her team published
their discovery of the supercluster, named after the constellation
Vela where it was found, in the Monthly Notices Letters of the Royal
Astronomical Society.

A
giant hiding behind the Milky Way

It
may be hard to believe that such a huge object could go unnoticed, but it makes
more sense when you consider where we all live. The Milky Way is our expansive
galactic home. It hosts more than 100 billion stars, trillions of planets, and
colourful clouds of gas and dust.

This
is especially true of objects behind the galactic plane, which is us looking
through the 100,000-light-year-wide disk of the Milky Way from the
inside-out. That cross-section of the Milky Way’s disk of stars, gas, and
dust is actually what we see when we look up in the sky in a very dark place:

Flickr/Abdul
Rahman

To
peer through it, Kraan-Korteweg and her colleagues combined the observations of
several telescopes: the newly refurbished South African Large Telescope (SALT)
near Cape Town, the Anglo-Australian Telescope (AAT) near Sydney, and X-ray
surveys of the galactic plane. Using that data, they calculated how fast each
galaxy they saw above and below the galactic plane was moving away from Earth.
Their number-crunching soon revealed that they all seemed to be moving together
- indicating a lot of galaxies couldn’t be seen.

"[I]t
became obvious we were uncovering a massive network of galaxies, extending much
further than we had ever expected," Michelle
Cluver, an astrophysicist at the University of the Western Cape, said in
the release.

The
researchers estimate that the Vela supercluster is about the same mass of the
Shapley Supercluster of roughly
8,600 galaxies, which is located about 650 million light-years away. Given
that the typical galaxy has about 100 billion stars,
researchers estimate that Vela could contain somewhere between 1,000 and
10,000 trillion stars.

Their
calculations also show Vela is about 800 million light-years distant and
zooming farther and farther away from us at a speed of about 40 million mph
(18,000 kilometers per second). Despite that extra and rapidly increasing
distance, however, Vela’s influence can’t be denied. The researchers estimate
that Vela’s gravitational tug on the Local Group of galaxies, which includes
the Milky Way, has sped them up by about 110,000 mph (50 kilometers per
second).

That’s
quite a pull, and could help tell the incredible story of how our Milky
Way galaxy - and we - got here.